Fuse holder for s-type fuses



May 13, 1969 w. F. BIENWALD ET AL 3,444,498

FUSE HOLDER FOR S-TYPE FUSES 'Filed oct. 1o, 1967 sheet of 2 ATTORNEYS May 13, 1969 w. F. BIYENWALD ET AL 3,444,498

FUSE HOLDER'FOR STYPE FUSES Filed oct. 1o, 1967 sheet 3 of 2 ATTORNEYS United States Patent O 3,444,498 FUSE HOLDER FOR S-TYPE FUSES Wolfgang F. Bienwald, Huntington Station, and Herbert W. Turn Suden, Jr., Floral Park, N.Y., assignors to Leviton Manufacturing Co., Inc., Brooklyn, N Y., a corporation of New York Filed Oct. 10, 1967, Ser. No. 674,239 Int. Cl. H01h 85/24 U.S. Cl. 337-226 Claims ABSTRACT OF THE DISCLOSURE A fuse holder for an S-type fuse which is dimensioned to permit mounting of the fuse holder in existing mounting panels and which has a molded one-piece receptacle body having an internally threaded socket cavity formed therein for reception of the threaded ceramic end of an S-type fuse. The socket cavity is open at its top and a center contact is located at the bottom of the socket cavity. A second or upper contact in the form of a iiat ring-shaped member is supported on an annular shoulder which surround-s the socket cavity at the top thereof. The upper contact has a terminal extension of Z-shlaped configuration and an elongated connecting link is attached thereto. The' terminal extension .is located in a recess formed in the annular shoulder surrounding the opening to the socket cavity and the connecting link extends through a passageway formed in the side walls of the receptacle body to the bottom thereof.

The present invention relates to ffuse holders and it relates, more particularly, to a fuse holder for an S-type fuse.

In the past, it has been customary to convert fuse holders for Edison type fuses into fuse holders for S-type fuses by means of adapters which :are screwed into the socket of the Edison type fuse holders. The adapter ernployed must correspond to the rating or current-carrying capacity of thegS-type fuse which is to be used. In other words, each adapter is designed for an S-type fuse of a particular capacity and a fuse of such capacity must be used to establish the desired power connection.

This arrangement is intended to prevent the installation of a fuse having a higher current-carrying capacity than that which the circuits are intended to carry and has been incorporated in electrical appliances such as stoves and the like to prevent possible overloading. However, the adapter represents an added item of expense and one of the objects of the present invention is to provide a fuse holder for an S-type fuse which does not require an adapter and thus, eliminate the cost thereof.

In addition, such adapters can be removed from Edison type fuse holders, even though force may be required to do so, -making it possible to install a fuse of higher capacity which will permit the passage of current in excess of the limits set by the appliance manufacturer and which may create hazardous conditions. Thus, another object of the present invention is to provide a fuse holder for an S-type fuse which will accept only a fuse of a currentcarrying capacity conforming to the limits set by the appliance manufacturer.

A further object of the present invention is to provide a fuse holder for S-type fuses which conforms dimensionally to the us-ual Edison type fuse holder and can be installed in a mounting panel or the like in place of the usual Edison type fuse holder without requiring changes in the panel or in the tools for producing the panel.

Another object of the invention is to provide .a fuse holder for an S-type fuse which incorporates means for ice snap-in mounting of the fuse holder in an opening in a mounting panel.

Other objects and advantages of the present invention will become apparent and will be better understood from the following description and the accompanying drawings, in which:

FIG. l is a top plan view of a fuse holder embodying the invention;

FIG. 2 is a side elevational view in partial section of the fuse holder shown in FIG. 1;

FIG. 3 is a bottom View of the fuse holder shown in FIG. l;

FIG. 4 is a section view taken along line 4-4 of FIG. l;

FIG. 5 is a top plan view of receptacle body forming part of the fuse holder shown in FIG. 1;

FIG. 6 is a section view taken along the line 6-6 of FIG. 5;

FIG. 7 is 'a side elevational view of a contact ring and connector link forming part of the fuse holder shown in F-IG. l;

FIG. 8 is a top plan view of the contact ring land connector link shown in FIG. 7;

FIG. 9 is a top plan .view of a thread ring forming part of the fuse holder shown in FIG. 1;

FIG. l0 is a side elevational view of the thread ring shown in FIG. 7; and

FIG. 11 is a fragmentary view in partial section illustrating a snap-in mounting for the fuse holder shown in FIG. 1.

Referring to the drawings in detail, there is a fuse holder 10 which includes a receptacle body or shell 11 which may be molded in one piece from an insulating material such as a phenolic resin.

The receptacle body has a central cavity or socket formed therein which is open at its top for receiving the threaded end of a standard S-type fuse (not shown). A standard S-type fuse has an enlarged or headed upper end with one contact being located beneath the headed end. The lower end or base of the fuse is made of -a ceramic material and has an external thread of square configuration formed thereon with the other contact member being located at the bottom of the ceramic portion.

The inner wall of the socket cavity in the receptacle body has a thread 12 of square configuration formed thereon which mates with the threads on the ceramic portion of the fuse. `In addition, the opening in the receptacle body which leads to the socket cavity is surrounded by an upstanding rim 13 which terminates at `an inwardly extending annular shoulder 14. The opening defined by the rim is slightly larger than the headed end of the fuse and when a fuse is screwed into the receptacle, the rim extends above and around the bottom of the headed end of the fuse so as to prevent accidental contact being made with the contact member carried immediately beneath the headed end of the fuse.

A vertical wall 15 extends downwardly from the inner circumference of the annular shoulder and terminates at a second inwardly extending annular shoulder 16 which extends around the opening to the socket cavity. A steel thread-clearing ring 17 and a contact ring 18 are seated on the second annular shoulder. The contact ring which is positioned above the thread-clearing ring engages with and makes electrical contact with the contact member carried beneath the headed end of the fuse and thus, establishes one of the power connections to the fuse.

As shown best in FIGS. 7 and 8, the contact ring includes a flat annular ring-shaped member 18a which is seated on the thread-clearing ring. A terminal extension 19 is formed at one side of the ring-shaped member. The terminal extension includes a leg 19a which extends downwardly and inwardly at a slight angle from the outer circumference of the ring-shaped member and a leg 19b which extends outwardly from the lower end of the first leg and at a level ybelow the ringshaped member. Thus, the ring-shaped member and the terminal extension have a generally Z-shaped configuration with the inner end of the lower leg being offset inwardly relative to the outer circumference of the ring-shaped portion and the outer end thereof extending partially over the side wall of the receptacle body. A connector link 20 in the form of an elongated, rod-shaped rivet is attached to the outwardly extending leg of the terminal extension and, as will be described later, extends through a passageway in the side wall of the receptacle body.

Diametrically opposite the terminal extension, there is a ring-retaining tab 21 which extends downwardly and outwardly from the outer circumference of the ringshaped mem'ber. These parts are formed of brass or other suitable electrically conductive material.

A recess 22 is formed in the upwardly facing annular shoulders which surround the, open end of the socket cavity and is shaped to receive the terminal extension of the contact ring. A- passageway 23 extends from the bottom of the recess through a side wall of the receptacle body to the ybottom thereof and the elongated connecting link or` rivet which is attached to the lower leg of the terminal extension extends through this passageway to the bottom of the receptacle body. This arrangement permits the receptacle body to have the same external dimensions as the usual Edison type fuse holder.

Opposite the terminal extension recess, a second recess 24 is formed in the upwardly facing annular shoulders to receive the ring-retaining tab of the contact ring. A lip 25 extends inwardly over the outer end of the ringretaining tab recess and engages with the ring-retaining tab when the contact ring is installed in the receptacle body.

A terminal plate 26 is connected to the lower end of the connector link on the exterior of the Ibottom of the receptacle body and holds the contact ring in place.

The thread-clearing ring which is held beneath the contact ring has a single thread convolution 27 with inwardly facing serrated teeth 28 formed thereon as shown inFIGS. 9 and 10, to clear the ceramic thread of the fuse as the fuse is screwed into place. The thread ring has an upper flange 29 which rests on the upwardly facing annular shoulder surrounding the socket cavity and this ange is interrupted by a depression on a slot 30 through which the ring-retaining tab carried by the contact ring extends.

A contact cup 31 is centrally located at the bottom of the socket cavity in the receptacle body. The contact cup has a raised center contact 32 which is positioned for engagement with the contact carried by the lower end of the fuse. The center contact may be in the form of an enlarged head of a rivet 33 which extends through a passageway 34 in the receptacle body which leads from the bottom of the cavity to the bottom of the receptacle body. A terminal plate 35 which is attached to the lower end of the rivet, serves to hold `the center contact and the contact cup in place.

As is customary with S-type fuses, the dimensions of the contact cup and center contact will depend upon the capacity of the fuse which is to be used and the dimensions of these parts may be varied for fuses of different ratings or current-carrying capacities.

The terminal plates may 'be provided with the usual terminal screw 36 for making wiring connections thereto or quick-connect terminals in the form of prongs may be provided if desired, An S-shaped rib 37 projects outwardly from the bottom of the receptacle body and separates the two terminal plates.

For mounting of the fuse holder in a panel or the like, attachment ears 38 are provided which project outwardly from opposite sides of the receptacle body at 4 the top thereof. The attachment ears contain openings 39 to receive mounting bolts or the like by which the fuse holder may be secured to a panel of an appliance. The spacing between the centers of the mounting openings is the same as the spacing for the usual Edison type fuse holder and thus, the subject fuse holder can be mounted in the usual opening on a mounting panel without changes being made therein.

As shown in FIG. 1l, spring or snap-in mounting clips 440 may be attached to each of the mounting ears by means of rivets 41 which extend through the openings in the mounting ears. The mounting clips have spring arms 42 which slope outwardly from the bottom of the receptacle 'body toward the top thereof, the upper portions of the arms sloping inwardly and then upwardly. The arms are forced inwardly as the fuse holder is being inserted in an opening in a mounting panel and whe-n the fuse holder has been fully inserted in the panel opening, the arms spring outwardly with the upper portions of the arms e-ngaging with the panel.

It will be understood that various changes and modiications may be made in the embodiment of the invention which has been illustrated and described herein without departing from the scope of the following claims.

1. In a fuse holder for an S-type fuse, the combination which comprises:

(a) a receptacle body of insulating material having a top and a bottom;

(b) said body including vertical side walls defining an internally threaded socket cavity which is open at. the top and closed at the bottom thereof and has a center contact located at the bottom thereof;

(c) an annular shoulder formed by said side walls;

(d) said annular shoulder extending around the open top of the socket cavity and having a recess formed therein;

(e) said side walls containing a passageway extending therethrough from said recess to the bottom of the receptacle body;

(f) an upper contact supported on said annular shoulder;

(g) a terminal extension connected to said upper contact and extending into said recess;

(h) said terminal extension including a leg extending downwardly and inwardly relative to the upper contact and a lower leg extending outwardly from said first leg at a level below said upper contact;

(i) an elongated connecting link attached to said lower leg of the terminal extension and extending through the passageway in the side walls of the receptacle body; and

(j) a terminal plate connected to the connecting link at the bottom of the receptacle body;

(k) said terminal plate engaging with the bottom of the receptacle body and holding the upper contact in place.

2. In a fuse holder for an S-type fuse, the combination as dened in claim 1 wherein:

(a) the annular shoulder extending around the socket cavity in the receptacle body has a second recess formed therein at a point opposite the recess for the terminal extension;

(b) a lip extending inwardly from the receptacle body and partially over said second recess at an outer end thereof; and

(c) a retaining tab extending downwardly and outwardly from the upper contact at a point opposite the terminal extension;

(d) said retaining tab extending into said second recess and beneath said inwardly extending lip.

3. In a fuse holder for an S-type fuse, the combination as defined in claim 1 which includes:

(a) a rim extending upwardly from the top of the receptacle body and extending around the socket cavity at a point spaced outwardly relative to the annular shoulder on which the upper contact is supported; (b) said upstanding rim dening an opening dimensioned to receive a headed end of an S-type fuse. 4. In a fuse holder for an S-type fuse, the combination as defined in claim 1 which includes:

(a) a thread-clearing ring supported on said annular shoulder beneath the upper contact. 5. In a fuse holder for an S-type fuse, the combination as defined in claim 1 which includes:

(a) mounting ears extending outwardly from opposite sides f the receptacle body at the top thereof;

(b) said mounting ears having openings therein at points beyond the exterior of the receptacle body. 6. In a fuse holder for an S-type fuse, the combination as defined in claim 5 which includes:

(a) spring mounting members attached to the openings in the mounting ears;

(b) each of said spring mounting members including a leg sloping outwardly from the bottom of the receptacle 'body toward the top thereof;

(c) said leg having an inwardly inclined upper end.

7. In a fuse holder for an S-type fuse, the combination as dened in claim 1 wherein:

(a) the upper contact comprises a ilat ring-shaped portion; and

(b) the downwardly and outwardly extending legs of the terminal extension are of a Z-shaped configuration.

8. A contact for an S-type fuse holder which comprises:

(a) a at ring-shaped member of conductive material;

(b) said ring-shaped member dening a central opening through which an end of the S-type fuse can pass;

(c) a terminal extension connected to said ring-shaped member at an outer circumferential edge thereof;

(d) said terminal extension including a leg extending downwardly and inwardly from said ring-shaped member and a lower leg extending outwardly from said rst leg at a level below said ring-shaped member; and

(e) an elongated connecting link connected to the outwardly extending leg of the terminal extension and extending downwardly therefrom;

(f) said connection being made at a point substantially in line with the outer circumferential edge of the ringshaped member.

9. A contact for an S-type fuse holder as dened in claim 8 which includes:

(a) a retaining tab extending downwardly and outwardly from the ring-shaped member at a point 0pposite the terminal extension.

10. A contact for an S-type fuse holder as defined in claim 8 wherein:

(a) the ring-shaped member and the terminal extension are formed from flat stock; and

(b) the connecting link is in the form of a rod.

References Cited UNITED STATES PATENTS 2,851,558 9/1958 Linton 337-195 3,056,872 10/1962 Kolton 337-191 3,177,318 4/1965 Lebens 337-195 3,225,164 12/1965 Linton 337-187 X 3,268,692 8/1966 Oldham 337--191 X 3,255,329 6/1966 Norden 337--226 BERNARD A. GILHEANY, Primary Examiner.

H. B. GILSON, Assistant Examiner.

U.S. C1. X.R. 337--191 

